Board and method for manufacturing a board

ABSTRACT

A board consisting at least of a substrate formed at least of a gypsum-based and/or cement-based basic material layer. The board is provided with a chamfer extending through the basic material layer.

This application claims the benefit under 35 U.S.C. 119(e) to the U.S.provisional applications 62/564,719 filed on Sep. 28, 2017.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to a board and a method of manufacturing suchboard.

More particularly, the invention relates to a board which is intendedfor forming a wall, floor or ceiling surface. In other words, thisrelates to a panel in the form of a wall panel and/or floor panel and/orceiling panel. More particularly, it relates to such board or panelwhich is of the type that is intended at least for being applied ininterior applications, in other words, for forming a floor covering,wall covering or ceiling covering.

SUMMARY OF THE DISCLOSURE

The invention aims at a board which, on the one hand, offers a goodresistance against fire and, on the other hand, is advantageous inrespect to production features and production possibilities, as well asin respect to processing.

To this aim, the invention relates to a board as described in theappended claims. Herein, several independent aspects will be covered,which are defined in the form of the appended independent claims.

To this aim, the invention relates to boards as defined in the followingnumbered paragraphs:

-   -   1.—Board, characterized in that it consists at least of a        substrate which is formed at least of a gypsum-based and/or        cement-based basic material layer with a compressive strength of        at least 30 kg/cm² and a resin-based covering provided on at        least one side of the substrate, in the form of a laminate layer        directly pressed onto the substrate, also named “DPL” (Direct        Pressure Laminate).    -   2.—Board according to paragraph 1, characterized in that the        directly pressed laminate layer is a layer which has been        pressed with a pressure of more than 25 kg/cm².    -   3.—Board according to any of the preceding numbered paragraphs,        characterized in that the basic material layer has a compressive        strength of at least 40 and still better at least 50 kg/cm².    -   4.—Board according to any of the preceding numbered paragraphs,        characterized in that the basic material layer has a compressive        strength of at least 70 kg/cm².    -   5.—Board according to any of the preceding numbered paragraphs,        characterized in that the basic material layer has a compressive        strength in the order of magnitude of 90 kg/cm² or more.    -   6.—Board according to any of the preceding numbered paragraphs,        characterized in that the directly pressed laminate layer is a        layer which has been pressed with a pressure of more than 30        kg/cm² and still better of more than 35 kg/cm², and that the        compressive strength of the board is higher than that value.    -   7.—Board according to any of the preceding numbered paragraphs,        characterized in that the basic material layer is a so-called        highly compacted gypsum and/or cement board.    -   8.—Board according to any of the preceding numbered paragraphs,        characterized in that the basic material layer contains        reinforcement material, such as reinforcement fibers, and        preferably consists of a gypsum fiber board or fiber cement        board, and more particularly of a highly compacted gypsum fiber        board or highly compacted fiber cement board.    -   9.—Board according to paragraph 8, characterized in that the        fibers are present in the basic material layer substantially        over the entire thickness of this layer.    -   10.—Board according to paragraphs 8 or 9, characterized in that        the fibers consist of synthetic fibers in general and/or natural        fibers in general and/or wood fibers and/or paper fibers and/or        carbon fibers and/or glass fibers.    -   11.—Board according to any of the preceding numbered paragraphs,        characterized in that the aforementioned resin-based covering is        situated at that side of the board which is intended for forming        the front side.    -   12.—Board according to any of the preceding numbered paragraphs,        characterized in that a resin bond is continuously present from        on the resin-based covering up into the gypsum-based and/or        cement-based material of the basic material layer.    -   13.—Board according to paragraph 12, characterized in that the        resin of said resin bond extends at least up to a depth in said        gypsum-based and/or cement-based material which is at least 0.5        millimeters and still better is at least 1 millimeter.    -   14.—Board according to any of the preceding numbered paragraphs,        characterized in that the substrate, at the side on which the        resin-based covering is provided, is free from a cover sheet,        such that the resin-based covering then is present directly on        said basic material layer.    -   15.—Board according to any of the paragraphs 1 to 13,        characterized in that the aforementioned substrate, at least on        the side on which the resin-based covering is provided,        comprises a cover sheet, which consists of one or more layers of        paper or cardboard or consists of another material, and wherein        the resin-based covering is provided directly or indirectly on        the paper or cardboard layer or other cover sheet.    -   16.—Board according to paragraph 15, characterized in that the        paper or cardboard layer has a thickness smaller than or equal        to 0.18 millimeters and still better smaller than or equal to        0.1 millimeter.    -   17.—Board according to any of the preceding numbered paragraphs,        characterized in that the substrate is provided with an        adherence-increasing layer, which improves the adherence of the        resin-based covering.    -   18.—Board according to any of the preceding numbered paragraphs,        characterized in that the aforementioned resin-based material        layer is formed of one or more material sheets pressed by means        of resin.    -   19.—Board according to paragraph 18, characterized in that at        least one of the material sheets, and preferably all of them,        consists, consist, respectively, of paper.    -   20.—Board according to paragraph 18 or 19, characterized in that        the resin-based material layer is at least formed of one or more        resin-impregnated sheets, more particularly paper sheets, which        are pressed on the substrate.    -   21.—Board according to paragraph 20, characterized in that the        resin-based material layer is at least composed of one of the        following layers, or comprises a combination of any two of the        following layers or all three of the following layers:        -   a sheet impregnated with resin, which sheet functions as a            basic or lower layer;        -   a sheet impregnated with resin, which sheet functions as a            decor layer;        -   a sheet impregnated with resin, which sheet functions as an            overlay and preferably is provided with particles which            increase the wear resistance, such as corundum.    -   22.—Board according to any of the preceding numbered paragraphs,        characterized in that it is provided with a decor layer, whether        or not with a pattern.    -   23.—Board according to paragraph 22, characterized in that the        pattern is a print directly provided on the board, for example,        realized by means of a digital printer, for example, inkjet        printer.    -   24.—Board according to any of the preceding paragraphs,        characterized in that in the upper side thereof a relief is        provided, formed by embossments, preferably realized when        compressing the laminate layer.    -   25.—Board according to any of the preceding paragraphs,        characterized in that it shows a pattern as well as embossments        in the surface and that the embossments are in register with the        image of the pattern.    -   26.—Board according to any of the preceding paragraphs,        characterized in that the resin consists of a thermo-hardening        resin, more particularly a melamine resin.    -   27.—Board, characterized in that it consists at least of a        substrate which is at least formed of a gypsum-based and/or        cement-based basic material layer with a resin-based covering        provided on at least one side of the substrate, in the form of a        laminate layer directly pressed onto the substrate, also named        “DPL” (Direct Pressure Laminate), wherein the board, on at least        two opposite edges, is provided with coupling means allowing to        couple two of such boards to each other.    -   28.—Board according to paragraph 27, characterized in that the        coupling means provide at least an overlap of material of the        substrate.    -   29.—Board according to paragraph 27 or 28, characterized in that        the coupling means provide at least a tongue and groove profile.    -   30.—Board according to paragraph 27, 28 or 29, characterized in        that the coupling means are configured such that they, in the        coupled condition, provide for a locking according to a        direction in the plane of the coupled panels and perpendicular        to the coupled edges, as well as in a direction perpendicular to        the plane of the coupled boards.    -   31.—Board according to paragraph 32, characterized in that the        coupling means are of the type which allows joining by means of        turning and preferably comprises a groove with a        further-extending rearmost lip, which is provided with a locking        element (8).    -   32.—Board, characterized in that it consists at least of a        substrate which is formed at least of a gypsum-based and/or        cement-based basic material layer; that the basic material layer        is provided with a reinforcement; that the board, on at least        two opposite edges, is provided with coupling means which allow        coupling two of such boards to each other, which are configured        such that they, in the coupled condition, provide for a locking        according to a direction in the plane of the coupled panels and        perpendicular to the coupled edges, as well as in a direction        perpendicular to the plane of the coupled boards; that the        coupling means are made substantially or entirely in one piece        in the basic material layer; and that the aforementioned        reinforcement is present up into the coupling means, wherein the        coupling means preferably are of the kind already described.    -   33.—Board according to paragraph 32, characterized in that the        reinforcement is formed by fibers which are present in the        material or the cement-based and/or gypsum-based basic material        layer, more particularly are blended therein, and thereby thus        also in the coupling means made in one piece therewith.    -   34.—Board, characterized in that it consists at least of a        substrate which is formed at least of a gypsum-based and/or        cement-based basic material layer; that the board, on at least        two opposite edges, is provided with coupling means which allow        coupling two of such boards to each other, which are configured        such that they, in the coupled condition, provide for a locking        according to a direction in the plane of the coupled panels and        perpendicular to the coupled edges, as well as in a direction        perpendicular to the plane of the coupled boards; that the        coupling means are realized substantially or entirely in the        board, and more particularly in the basic material layer; and        that the board comprises a usage side which is untreated or is        provided with a semi-finished covering.    -   35.—Board, characterized in that it consists at least of a        substrate which is formed at least of a gypsum-based and/or        cement-based basic material layer; that the board, on at least        two opposite edges, is provided with coupling means which allow        coupling two of such boards to each other, which are configured        such that they, in the coupled condition, provide for a locking        according to a direction in the plane of the coupled boards or        panels and perpendicular to the coupled edges, as well as in a        direction perpendicular to the plane of the coupled boards; that        the coupling means are realized substantially in one piece or        entirely in one piece in the basic material layer; and that the        board is oblong with a length of at least 2.4 meters, wherein        the aforementioned edges which comprise the aforementioned        coupling means, are formed by the longitudinal edges, wherein        the coupling means preferably are of the kind and form already        described earlier.    -   36.—Board, characterized in that it consists at least of a        substrate which is formed at least of a gypsum-based and/or        cement-based basic material layer; that the board, on at least        two opposite edges, is provided with coupling means which allow        coupling two of such boards to each other, which are configured        such that they, in the coupled condition, provide for a locking        according to a direction in the plane of the coupled boards and        perpendicular to the coupled edges, as well as in a direction        perpendicular to the plane of the coupled boards; that the        coupling means are realized substantially in one piece or        entirely in one piece in the material of the board, and more        particularly in the material of the aforementioned basic        material layer; and that the board comprises a useful surface        with a surface size of at least 0.5 square meters and still        better at least 0.75 square meters, wherein the coupling parts        preferably are of the kind and form already described above.    -   37.—Board, characterized in that it consists at least of a        substrate which is formed at least of a gypsum-based and/or        cement-based basic material layer; that the board, on at least        two opposite edges, is provided with coupling means which allow        coupling two of such boards to each other, which are configured        such that they, in the coupled condition, provide for a locking        according to a direction in the plane of the coupled boards and        perpendicular to the coupled edges, as well as in a direction        perpendicular to the plane of the coupled boards; and that the        coupling means are provided with a means or element, more        particularly in the form of a material layer and/or material        strip, which provides for a sealing and/or for a tensioning        force, which presses the panels with a tension, more        particularly, so-called pretension, against each other.    -   38.—Board, characterized in that it consists at least of a        substrate which is formed at least of a gypsum-based and/or        cement-based basic material layer; that the board, on at least        two opposite edges, is provided with coupling means which allow        coupling two of such boards to each other, which are configured        such that they, in the coupled condition, provide for a locking        according to a direction in the plane of the coupled boards and        perpendicular to the coupled edges, as well as in a direction        perpendicular to the plane of the coupled boards; and that the        coupling means are provided with a means or element, preferably        in the form of a material layer and/or material strip, which        provides for a temperature-activatable sealing.    -   39.—Board, characterized in that it consists at least of a        substrate which is formed at least of a gypsum-based and/or        cement-based basic material layer; that the board, on at least        two opposite edges, is provided with coupling means which allow        coupling two of such boards to each other, which are configured        such that they, in the coupled condition, provide for a locking        according to a direction in the plane of the coupled boards and        perpendicular to the coupled edges, as well as in a direction        perpendicular to the plane of the coupled boards; that the        coupling means are realized substantially in one piece or        entirely in one piece in the board, and more particularly in the        basic material layer; and that in the proximity of the front        side of the board, at the corner edge between the front side and        at least one, and preferably both of said two edges, a chamfer        is present in the form of a bevel or rounding; that the board        comprises a covering or top layer; and that the chamfer        preferably extends deeper than the thickness of the covering or        top layer and thus extends at least up into the basic material        layer, wherein the surface of the chamfer does or does not        comprise a covering, preferably a separate covering. Such        chamfer is particularly useful with thin top layers, thinner        than 1 or 2 mm, as then, due to the chamfer, the risk of        splitting and delamination at the edges is minimized, which        otherwise is a real risk with thin top layers. In particular in        combination with a covering of said DPL, or panels, which, as        aforementioned, are provided with DPL, this is of importance.        Also, herein improved effects are obtained when, as will be        described below, fillers and/or fibers are applied, which        preferably then in fact are present up to against the underside        of the top layer, or at least up to a distance of less than 1 mm        underneath/behind the top layer.    -   40.—Board, characterized in that it consists at least of a        substrate which is formed at least of a gypsum-based and/or        cement-based basic material layer; that the board, on at least        two opposite edges, is provided with coupling means which allow        coupling two of such boards to each other, which are configured        such that they, in the coupled condition, provide at least for a        locking in a direction perpendicular to the plane of the coupled        boards, preferably by means of a tongue and groove; that the        coupling means are realized substantially or entirely in one        piece in the basic material layer; and that the groove is        bordered by a foremost lip and a rearmost lip, wherein the        rearmost lip, distally seen, extends farther than the foremost        lip, and wherein the rearmost lip is nailable and/or screwable        and/or comprises appliances for facilitating the nailing and/or        screwing, and/or is configured such that the board can be        attached with the lower lip by means of a clip against an        underlying surface or underlying structure.    -   41.—Board according to paragraph 40, characterized in that        coupling means, as described before, are applied.    -   42.—Board according to any of the preceding numbered paragraphs,        characterized in that the cement-based and/or gypsum-based basic        material layer is formed of a substance bonding by means of a        liquid, more particularly by hardening a gypsum-based and/or        cement-based mass.    -   43.—Board according to any of the paragraphs 1 to 41,        characterized in that instead of a cement-based and/or        gypsum-based basic material layer, use is made of another        mineral-based composed material and/or of a geopolymer.

Further, it is so that with cement-based boards, at least two issuesmanifest themselves.

A first problem is that these boards absorb moisture, water,respectively, due to the porosity of the board and due to capillaryeffect. Moreover, cement-based boards in their normal quality are veryalkaline. They comprise many salts and, when taking in moisture andsubsequently drying out, there is a migration of alkaline water andsalts. In the case of façade boards, for which cement-based boards areoften used, the cement-based substrate of the board is coated at therear and upper sides with a lacquer or paint which is not 100%water-impervious, and there is natural ventilation, such that no issuewill occur. In the case one wants to apply cement-based boards in afloor covering, more particularly a floor covering which is floatinglyinstalled, wherein these boards are provided at the edges withmechanical coupling parts, such as milled coupling profiles, forcoupling them to each other, such board, possibly on both sides, thus,the upper side and the underside, shall be provided with a coveringwhich offers the necessary resistance against wear resistance and waterabsorption. As a result of the fact that such cement-based boards madeas floor panels are lying on the subfloor, as well as due to the factthat such coverings will be present, no significant ventilation of thecement-based substrate can occur. The board can absorb moisture via themilled coupling profiles, and when drying, the alkaline water and thesalts slowly will damage the primer, which finally leads to the coveringcoming loose.

A second problem is that standard cement-based boards have a relativelysmall internal bond. A standard cement-based board actually issystematically composed of various thin layers, which is a feature ofthe Hatschek production process mostly applied therewith. This resultsin a relatively small internal bond, such that it is not evident toconsider such standard cement-based board as a floor panel, wall panelor ceiling panel, at least not when edges or profiles have to beprovided thereon by a machining treatment. In fact, the small bond maylead to chipping at the edges. There is also a risk that, as a result ofthe weak internal bond, after milling of locking coupling means, gapingedges and cracks occur in the locking means, such that the floor is notperformant during placement and after installation.

According to various aspects of the invention, herein below a number ofsolutions are presented, which are described in the numbered paragraphsfollowing herein below:

-   -   44.—Board, more particularly a panel in the form of a floor        panel and/or wall panel and/or ceiling panel, preferably of the        type which is at least intended for interior application,        wherein this panel comprises a basic material layer (or        substrate) which is cement-based, which basic material layer as        such can comprise one or more layers of cement-based basic        material, wherein this panel preferably comprises a top layer,        which as such can consist of one or more layers and gives a        decorative appearance to the panel, and that the panel is        provided with means which restrict moisture intake in the basic        material layer, and/or with means which improve the internal        bond in the basic material layer.    -   45.—Board, more particularly a panel, according to paragraph 44,        characterized in that the aforementioned means which improve the        moisture intake in the basic material layer and/or the internal        bond in the basic material layer, are present according to at        least one of the following possibilities:        -   the means are applied at least in the proximity of the front            side (or thus upper side in the case of a floor panel)            and/or rear side (or thus underside in the case of a floor            panel) of the basic material layer, more particularly at the            respective surface of the basic material layer and/or            directly thereunder;        -   the means are applied almost exclusively or exclusively in            the proximity of the front side (or thus upper side in the            case of a floor panel) and/or rear side (or thus underside            in the case of a floor panel) of the basic material layer,            more particularly at the respective surface of the basic            material layer and/or directly thereunder, whereas the            respective means are not or almost not present in the middle            of the basic material layer;        -   the means are employed over the entire thickness of the            basic material layer.    -   46.—Board, more particularly a panel in the form of a floor        panel and/or wall panel and/or ceiling panel, preferably of the        type which is at least intended for interior application,        wherein this panel comprises a basic material layer (or        substrate) which is cement-based, which basic material layer as        such can comprise one or more layers of cement-based basic        material, wherein this panel preferably comprises a top layer,        which as such can consist of one or more layers and gives a        decorative appearance to the panel, and that the panel comprises        means (by which also provisions can be understood) which result        in an improved adherence of the top layer and/or provide a        reinforcement and/or lesser moisture intake, and wherein this        panel in respect to these means preferably also meets paragraphs        44 and 45, characterized in that the panel shows one or more of        the following characteristics (wherein in the case of a        combination any not contradictory combination of two or more        characteristics has to be considered a possibility according to        the invention):        -   the aforementioned means are of such a nature that they, at            least on or next to a surface of the basic material layer,            and preferably at least at the side where a top layer or            backing layer is to be provided, seen in the thickness of            the panel, provide for a zone which is alkaline-resistant            and/or the alkaline resistance of which is improved;        -   the aforementioned means are of such a nature that they, at            least on or next to a surface of the basic material layer,            and preferably at least at the side where a top layer or            backing layer is to be provided, a reaction with water from            the atmosphere and/or from the basic material layer takes            place, (to this aim, for example, a “silres” product from            the “Wacker” company can be applied, for example, silres            BS1701, which can be applied in pure form and then reacts            with the water;        -   the aforementioned means make use of a means which enhances            hydrophobicity, which means is incorporated into the            cement-based basic material layer, preferably at least on or            next to the surface thereof;        -   the aforementioned means make use of a means which forms a            filler and/or matrix of material which is water-impervious            and/or water-repellent;        -   the aforementioned means provide for the application of a            silane- and/or siloxane-containing liquid, more particularly            emulsion; (after application of the product, preferably as a            coating, a hydrolysis is starting which breaks the emulsion,            alcohol is released and a silicone matrix is formed which is            water-repellent; herein, everything is alkaline-resistant);            to this aim, for example, a product of the “silres” kind of            “Wacker” can be applied, for example, in the case of silres            BS3003 this can be applied with a 1:5 to 1:15 dilution in            water and 0.1-3% of active material (preferably in the order            of magnitude of 1%) to the total binder in the basic            material layer;        -   the means stated in the preceding 5 paragraphs is applied in            that it is introduced into the substance, and more            particularly wet matter (slurry) of which the cement-based            material layer is formed, preferably during a Hatschek            process;        -   the aforementioned means stated in the first 5 paragraphs is            applied via impregnation, more particularly after forming            the cement-based basic material layer, for example, after a            production according to the Hatschek process;        -   the means stated in the preceding paragraph is applied via a            coating technique, preferably by means of an excess of            product, and/or preferably by means of a roller and more            particularly by a twice wet on wet coating;        -   the aforementioned means consist in adding so-called metal            soaps (for example, Bärlocher products); for example, to            this aim use can be made of aluminum/magnesium/calcium/zinc            stearate and/or zinc laurate long chain fatty acid            tail+metal); preferably, this is added into the wet material            mass (slurry paste, for example, at 0.1-1% of dry weight;            the addition reduces capillary effect and moisture intake in            the board);        -   the aforementioned means consist in adding, an additive,            respectively, of hydrophobic powder, for example, on the            basis of silane or silicone resin (for example, DOW            SHP50/60); preferably, it is added into the slurry paste,            for example, at 0.1-2%, and preferably 0.25-0.5% of dry            weight; this is more performant than stearates and            silane/silicone emulsions;        -   the aforementioned means consist in adding, an additive,            respectively, of silicates with hydrophobic features, for            example, Li-silicates; the effect thereof is double. On the            one hand, CaOH is reacted away towards CaCO3 and in this            manner the board is reinforced and made less sensitive to            aging. On the other hand, a water-repellent effect is            obtained;        -   as an alternative for the aforementioned silane,            polyurethane is applied, preferably water-based            polyurethane, and more particular of the type polyester or            polyether, and more particularly polycaprolactone; wherein            this polyurethane preferably is applied together with a            crosslinker as an adhesion promoter, more particularly a            carbodiimide crosslinker; this is particularly useful with a            DPL top layer, as such crosslinker will show its advantages            best as an adhesion promoter between melamine and fiber            cement board;        -   the aforementioned means consist in the use of a            crosslinker, preferably carbodiimide, for forming an            improved connection between a fiber cement board and a top            layer, more particularly melamine-based top layer;        -   the aforementioned means (by which products can be            understood as well as measures or operations which then            offer a result at the product) provide for one of the            following possibilities, or a combination thereof:        -   means which provide for a reduction of the porosity of the            basic material layer and/or a reduction of the capillary            effect thereof and/or an increase of the density thereof;        -   the use of cement (in the slurry) with a smaller PSD            (Particle Size Distribution), preferably smaller than usual            in commercial cement boards;        -   the use of comparatively more cement than usual in            commercial cement boards;        -   increasing the amount of silica or other pozzolane material            in comparison to commercial cement boards;        -   impregnating the cement-based basic material layer with a            low-viscosity dispersion which reinforces the basic material            layer or thus board or substrate, for example, by means of            acrylate or epoxy or isocyanate; the impregnation may take            place by, for example, vacuum and/or pressure;        -   in the case of a Hatschek process, increasing the            interlaminary bond, for example, by processing wetter and            applying a Hatschek cylinder or sieve which is somewhat            coarser than with the usual techniques (larger surface/mm²)            and/or by, for example, applying a binding agent between            each cement layer, for example, by spraying;        -   after the Hatschek process (or any other basic shaping            process) and prior to the press and/or prior to hardening,            coating and/or impregnating with a thermoplastic-based            substance (dispersion); herein, the exothermal reaction of            the cement renders the thermoplastic liquid, such that it            can penetrate into the entire board, or anyhow at least at            the surface thereof, where, for example, the top layer has            to be provided; applying one or more of the following            chemical products in the basic material layer: acrylic and            metacrylic (co)polymers, PVA or EVA polymers,            styrene/acrylic acid ester copolymers, silane or siloxane of            silicone.    -   47.—Board according to any of the paragraphs 44 to 46,        characterized in that the herein above-mentioned means, and more        particularly the therein-applied products which result in        hydrophobic features, as far as not contradictory with the        preceding, are applied alternatively either by providing them in        the mass of the board or thus of the cement-based basic material        (in the slurry), or by impregnation and/or by providing them in        the form of a pre-primer, or by providing a combination thereof        (via this technique, the edges of the panels can be treated as        well, in particular the surface of coupling parts formed        thereon, in particular milled coupling parts allowing a        mechanical locking).

It is clear that according to the invention preferably a top layerprovided on the basic material layer is present, which as such canconsist of one or more layers.

The panel thicknesses of the finished products can be at choice,however, in the case of floor panels the overall thickness preferably isless than 8 mm and still better less than 6 mm, and possibly even lessthan 4 mm.

In the case of all embodiments mentioned herein above as well as belowand in the claims, in the case of a cement-based basic layer preferablyuse shall be made of fiber cement, thus “fiber cement board”, in Dutchsometimes also called cement fiberboard.

There, where this is not contradictory to the description and claims,the cement-based substance according to the invention may also bereplaced by other mineral-based substances, such as, for example,calcium oxide board.

It is noted that the various independent aspects according to theinvention can be combined at choice and that all mathematicalcombinations which do not include any contradictions, have to beconsidered inventions. Further, it is also possible to detach allcharacteristics of dependent claims as such from the independent claimto which they refer and to combine them with the characteristics of oneor more of the other independent claims, this as far as this does notresult in contradictory characteristics. Here, too, all mathematicalcombinations have to be considered disclosed.

The invention also relates to a method of manufacturing such board,which method can be derived from the composition of the board describedin the claims.

Regarding the use of lacquers, paints, coatings and the like, accordingto the invention preferably use is made of one or more of the followingpossibilities, wherein this primarily is intended for being applied withcement-based boards, in particular with fiber cement boards:

Backside lacquer:

-   -   Water-based PVDC lacquer, for example, Haloflex 202;    -   UV-curable so-called clearcoat lacquers (as alkali-resistant        binder)        Waterbased Preprimer    -   with solid components of 20-60% and application weight of 20-600        g/m²;    -   to be applied by brush, roller, spraying, curtain coating and/or        impregnation by means of vacuum or pressure;    -   chosen from the following suitable primers: acrylic and        methacrylic (co)polymers, PVA or EVA polymers, styrene/acrylic        acid ester copolymers;    -   the primer comprises hydrophobic additives, for example,        so-called metal soaps, fluorinated additives, silanes, siloxanes        and the like;    -   the primer comprises fillers, for example, aluminosilicates,        silicates, alkaline-earth metal carbonates, calcium carbonates;    -   the primer comprises pigments, more particularly        alkali-resistant pigments or metal oxides; the primer comprises        crosslinkers, for example, isocyanates, silanes and the like,        which effect an extra crosslinking with the mineral board;        UV Primer:    -   application weight 20-40 g/m² with solid components of 100%; UV        acrylic lacquer with alkali-resistant binder;    -   UV acrylic resin, preferably with a functional isocyanate group;    -   with an addition of a crosslinker, more particularly        isocyanates, silanes and the like, or creation of a        two-component curing mechanism; it is noted that isocyanate will        chemically react with OH, NH₂ and other functional groups in the        fiber cement board.        UV Sealer:    -   application by means of a so-called putty machine, wherein all        small openings and gaps are filled, whereby it is made sure that        a moisture barrier is created between the fiber cement board and        the following layers, for example, white lacquers;    -   application weight 20-50 g/m², 100% solids;        Application of Other (Following) Layers:    -   UV white lacquer;    -   inkjet receiver coating;    -   digital print;    -   protective anti-abrasive lacquers, which contain, for example,        aluminum oxide.

All lacquers preferably are alkaline-resistant, as after installationand during cleaning, there is always a small risk that water, whichcontains salts of the fiber cement board, can penetrate through thelacquer layers.

The invention, as far as this relates to cement-based boards, moreparticular fiber cement boards, also relates to boards, more particularpanels, which meet well-defined specifications, whereby they are moresuitable for interior applications, such deviating from thespecifications which commonly are applied for façade boards.

According to the invention, the boards, panels, respectively, thenpreferably meet one or more of the specifications stated in thefollowing table, wherein combinations at choice are possible. Herein, acomparison is made between the specifications of common fiber cementboards, which usually are applied for exterior façades, and fiber cementboards, of which the specifications now according to the invention arechosen such that they can be usefully applied as floor panels, inparticular for interior applications. The boards are also suitable forwall and ceiling applications, considering that those mostly have lessstrict requirements than floor panels.

Not coated Not coated board Coated board composition as according to theaccording to the a façade board invention for invention for (prior art)floor application floor application Density 1800-1850 1870-20001870-2000 (kg/m³) Tensile <1.3 >1.4 and >1.4 and strengthpreferably >1.5 preferably >1.5 (N/mm²) Pull-off <1.5 >1.6 and >1.6 andstrength preferably >1.8 preferably >1.8 (N/mm²) 24 h H2O    5-10% <5%,preferably <5%, preferably absorption <3%, and still <3%, and stillbetter <1.5% better <1.5% max. H2O +13% and can <11%, preferably <6%,preferably absorption go to +25% <10%, and still <3%, and still better<8% better <1.5% Dimensional +/−0.25-0.5% <+/−0.15%, and <+/−0.05%, andstability better <+/−0.1% better <+/−0.04% Delta 0.25-0.6 mm <0.2 mm and<0.2 mm and thickness preferably preferably tolerance <0.1 mm <0.1 mmfor panel of 6 mm

It is noted that according to the invention each criterion mentioned inthe above table has to be considered separately as inventive idea, thus,each criterion from one box of the table, as well as any possiblecombination of two or more criteria.

It is also clear that the absorption is expressed in percent by weight,thus, the increase in weight of the board before and after the H2Oabsorption.

It is clear that, when determining the aforementioned absorption, it isstarted from a dry or approximately dry board, in other words, a boardwhich, apart from the chemically bound moisture, comprises no orapproximately no vaporable moisture. It is preferred that in practiceherein it is started from an air-dried panel, wherein the air-driedcondition is obtained by drying the board in an oven at 105° C., withsuction, such during 3 days. The H2O absorption then is measured byplacing the board in water, such as tap water, such during 24 hours forthe “24 h absorption” and during a considerably longer time for the“max. H2O absorption”, by which is meant up to a condition in which thewater absorption curve is approximately flat. Practically, to this aim 3days can be chosen at atmospheric pressure.

Preferably, the boards according to the invention indeed are subjectedto a grinding treatment before providing them with a covering.

The following criteria can also be applied:

Coated composition Coated board according as façade board to theinvention Pull-off and tear Between 10 and 25 >25, preferably >30strength and still better >35

One or more of the above-mentioned specifications (specs) of the boardsaccording to the invention thus will preferably be maintained.Primarily, they are substantially intended for boards which have to beprovided with lacquer or are provided with lacquer. With any othercoverings, too, for example, a melamine layer pressed thereon, it isadvantageous to work with boards which meet the specs stated hereinabove according to the invention.

The application of one or more of the criteria of the invention effectthat the boards are particularly suitable for application as floorpanels, wall panels and ceiling panels, and the more of theaforementioned criteria are applied, the better the board, the panel,respectively, is for such applications, by which is meant that the boardor the panel is more resistant against damages during and afterproduction, undesired deformations and excessive expansion, and/or thatthe uncoated board is more suitable for forming, starting therewith, afinished product, in other words, more suitable for providing a coveringthereon and/or providing coupling means, more particularly horizontallyand vertically locking coupling means, herein.

The criteria thus as such already form an invention. It is noted thatthese criteria may be achieved in any manner, and to this aim allpossibilities aforementioned for this purpose can be employed, as wellas other possibilities which are within the range of the person skilledin the art.

In order to obtain that the not-coated board fulfills the requiredcriteria, in particular in respect to water absorption and dimensionalstability, influence is taken on the composition of the material of thebasic material layer, for example, by, as aforementioned, increasing thehydrophobicity of the fiber cement.

In order to obtain that the not-coated board fulfills the requiredcriteria, in particular in respect to water absorption and dimensionalstability, either influence can be taken on the composition of thematerial of the basic material layer, for example, by, asaforementioned, increasing the hydrophobicity of the fiber cement, orinfluence can be taken on the moisture-proof protection towards theoutside, or influence can be taken on both. By “protection towards theoutside” is meant that at least on portions of the surface layers ofwhich kind whatsoever are present, which prevent or mitigate moisturepenetration and other negative influences. By applying the layers, thebasic material layer can be partially or entirely encapsulated such thatthe water absorption fulfills the intended criteria. The covering layerprovided on the decorative side can be realized as an impermeable layer.A possible backing layer also can be realized as an impermeable layer.Finally, if this is necessary in order to achieve one or more of thedesired criteria, also the coupling means, mostly the milled lockingtongue and locking groove, can be provided with a coating and/orimpregnation which reduce and/or exclude the absorption of moisture andwater along the edges. To what extent such measures have to be applied,then can be determined by the person skilled in the art via tests, suchthat the board fulfills the respective criteria required according tothe invention.

It is noted that one of the most important criteria from the abovetable, as well as an independent characteristic, is the fact that thenot-coated board fulfills the aforementioned criterion of the low 24 hH2O absorption, in other words, that this is lower than 5%, andpreferably is lower than 3% and still better is lower than 1.5%.

Another important criterion from the table, as well as an independentcharacteristic, is the fact that the coated board, by which the entirelyfinished panel is meant, fulfills the aforementioned criterion of thelow 24 h H2O absorption, in other words, that this is also lower than5%, and preferably lower than 3% and still better lower than 1.5%.

According to an embodiment the invention also relates to a board, asdefined in any of the herein above-described embodiments (from thenumbered paragraphs as well as from other described possibilities), moreparticularly a panel in the form of a floor panel and/or wall paneland/or ceiling panel, preferably of the type which is at least intendedfor interior application, wherein this panel comprises a basic materiallayer or substrate which is cement-based, which basic material layer assuch can comprise one or more layers of cement-based basic material,wherein one or more of these layers, and preferably the entire basicmaterial layer, preferably is on the basis of fiber cement, wherein thispanel comprises a top layer which preferably gives a decorativeappearance to the panel, and thus provides in a coating, either lacquerand/or print and/or layer adhered thereto, characterized in that thebasic material layer, apart from the cement, also comprises fibersand/or fillers and/or filling agents, preferably additionally topossible process fibers, wherein these fillers and/or fibers preferablyconsist of synthetic material and/or glass and/or crystalline calciumsilicate (including hydrate) and/or xonolite and/or tobermorite and/orinosilicate and/or gyrolite and/or wollastonite and/or sepiolite and/orrhyolite and/or basalt and/or rock wool and/or diabase and/or pumiceand/or chalk and/or limestone and/or talc, wherein in the case ofapplication as a particle-shaped filler, this filler preferablycomprises particles which are comprised between 1 and 200 microns and/orthis filler preferably forms at least 10 percent by weight of the drycement mixture.

The use of such fillers and/or fibers, more particularly on the basis ofthe aforementioned materials, has an advantageous effect on the qualityof the basic material layer and thus also the quality of the couplingparts realized therein.

Herein, it is further preferred that the board is characterized in thatit, on at least one pair of edges, is provided with coupling parts whichallow a mutually locking coupling, with a tongue and groove structure orwith hook-shaped elements which engage one behind the other, and/or witha separate locking part provided in a seat in an edge, more particularlya locking part which preferably consists of synthetic material, and thatthe fillers and/or fibers are not only centrally present in the board,but also are present in the tongue structure and/or in the groovestructure, by which then the lips are meant which border the groove,and/or in the hook-shaped elements and/or in said seat, by which thenthe walls are meant which surround the seat.

Further, hereby it is preferred that the tongue structure and/or groovestructure and/or hook-shaped elements and/or seat are manufactured bymeans of a milling treatment and thus comprise milled surfaces.

The presence of the fillers and/or fibers improves the strength of thecoupling parts and also allows a better treatment in order to arrive atsuch coupling parts, amongst others, by milling. The use of wollastoniteleads to particularly good results.

It is noted that coupling parts which allow a mutually locking couplingare known as such. An example of coupling parts with a tongue and groovestructure in a floor panel is known, amongst others, from FIG. 11 of WO2014/108875 and from the FIGURES of WO 97/47834. Herein, the couplingparts, according to the present invention, preferably are realized inone piece from the basic material layer. An example of coupling partswith hook-shaped elements which engage behind each other and/or with aseparate locking part provided in a seat in an edge, more particularly alocking part which provides in a locking according to a directionperpendicular to the panels, is known from, amongst others, the FIGS.12, 14, 15 and 16 of WO 2014/108875. An example of integral couplingparts with hook-shaped elements is known from FIG. 7 of WO 01/75247.

These basic forms of coupling parts also have to be understood asincorporated by reference to WO 2014/108875, WO 97/47834 and WO01/75247.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically represents a preferred embodiment of such board 1,wherein it is attached as a wall covering board or wall panel against alath structure 2.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The basic material layer 3 is a gypsum or fiber cement board. On top ofthis, a DPL layer 4 is pressed, which as such comprises one or moreresin-impregnated sheets. Possibly, a counter layer 5 is provided.Compressing usually is performed at an increased temperature.

The coupling means 6 preferably are of the type which locks in twodirections D1 and D2, as indicated. Preferably, they are also of thetype which allows joining by means of a turning movement R.

As represented, herein preferably use is made of a longer rearmost lip7, which is provided with a locking element 8.

At the front corner edge a chamfer 9 can be provided.

A preferably strip-shaped element 10, preferably provided at the lockingelement 8, can result in a pretension and/or result in a seal and/orresult in a heat-activatable fire-retarding joint.

A recess 11 offers space for the head of a nail or the like, such thatthe whole is nailable or screwable.

Of course, the present invention is not limited to the examplerepresented in the FIGURE.

Also, the FIGURE is schematically illustrative for floor panels, whereinthen the back side of the represented panel has to be understood asunderside. Locking coupling parts and other characteristics, such aschamfers 9 including a covering 12, can be employed analogous in floorpanels.

The most intended applications of the invention are floor panels andwall panels. With wall panels, this preferably are room-high panelswhich are provided with coupling parts at their edges, which edges areto be mounted vertically, said coupling parts being, for example, of thetype as represented in the accompanying FIGURE. With floor panels, thispreferably relates to smaller panels, which are provided at their fouredges with coupling parts allowing a mutual coupling and locking, inorder to be able to form, as usual, a so-called floating floor covering.Wall panels of fiber cement have the great advantage to befire-resistant, whereas floor panels of this material will hardly expandas a result of temperature changes and the like.

The invention also relates to the obtained substrates as such, withoutthese being already finished further by means of top layers or the like.

It is noted that all information comprised in WO 2018/138273 also has tobe understood as incorporated in the present application, as alternativepossibilities in combination with the herein above-describedpossibilities of the present application.

According to another preferred embodiment, the coupling parts areprovided with a waterproof or moisture-repelling substance.

In a particular embodiment, the invention relates to a board, moreparticularly a panel in the form of a floor panel and/or wall paneland/or ceiling panel, preferably of the type which is at least intendedfor interior application, wherein this panel comprises a basic materiallayer or substrate which is cement-based, which basic material layer assuch can comprise one or more layers of cement-based basic material,wherein one or more of these layers and preferably the entire basicmaterial layer preferably is on the basis of fiber cement, wherein thispanel comprises a top layer which comprises one or more syntheticmaterial layers, which, at least in their entirety, have a thickness of0.5 and still better 1 mm. This can be a vinyl-based layer, such as withLVT. In this manner, delamination in the fiber cement is avoided as thetop layer then is sufficiently strong.

Alternatively, the top layer can also be a HPL layer glued onto thebasic material layer. Such HPL layer provides for a strong surface, anddelamination is almost excluded.

The invention claimed is:
 1. A board consisting at least of a substrateis formed from a basic material layer based on a material selected froma group consisting of gypsum, cement and geopolymer; wherein the board,on at least two opposite edges, is provided with coupling means arrangedfor coupling two of such boards to each other, said coupling means areconfigured such that, in a coupled condition, the coupling means providefor a locking according to a direction in a plane of the coupled boardsand perpendicular to the coupled edges, and in a direction perpendicularto the plane of the coupled boards; wherein the coupling means arerealized substantially in one piece or entirely in one piece in thebasic material layer; and wherein in a proximity of a front side of theboard, on a corner edge between the front side and at least one, of saidtwo opposite edges, a chamfer is present, in a form of a bevel orrounding; wherein the board comprises a covering or top layer; whereinthe covering or top layer is thinner than 1 mm; and wherein the chamferextends deeper than a thickness of the covering or top layer and extendsat least into the basic material layer from the covering or top layerfrom the front side of the board, wherein a surface of the chamfercomprises a separate covering from the covering or top layer on theboard.
 2. The board according to claim 1, wherein the board comprisesone or more fillers or fibers.
 3. The board according to claim 1,wherein the basic material layer of the substrate is gypsum or cementand has a compressive strength of 30 kg/cm2, and the top layer orcovering layer is resin-based and provided on at least one side of thesubstrate, in a form of a laminate layer directly pressed onto thesubstrate.
 4. The board according to claim 3, wherein the board has atleast one of the following characteristics: wherein the laminate layeris directly pressed with a pressure of more than 25 kg/cm2; wherein thebasic material layer has a compressive strength of at least 40 kg/cm2;wherein the basic material layer has a compressive strength of at least70 kg/cm2; wherein the basic material layer has a compressive strengthin an order of magnitude of 90 kg/cm2 or more.
 5. The board according toclaim 3, wherein the laminate layer is directly pressed with a pressureof more than 30 kg/cm2, and that the compressive strength of the boardis higher than 30 kg/cm2.
 6. The board according to claim 1, wherein thebasic material layer is formed from gypsum or cement.
 7. The boardaccording to claim 1, wherein said covering or top layer is resin-basedand a resin bond is continuously present from on the covering up intothe basic material layer, wherein the basic material layer is formedfrom gypsum or cement.
 8. The board according to claim 7, wherein theresin of said resin bond extends at least up to a depth in the basicmaterial layer, wherein said depth is at least 0.5 millimeters.
 9. Theboard according to claim 7, wherein the substrate, at the side on whichthe resin-based covering is provided, is free from a cover sheet, suchthat the resin-based covering is directly present on said basic materiallayer.
 10. The board according to claim 7, wherein the substrate, atleast on a side on which the resin-based covering is provided, comprisesa cover sheet, which consists of one or more layers of paper orcardboard or consists of another material, and wherein the resin-basedcovering is provided directly or indirectly on the paper or cardboardlayer or other cover sheet.
 11. The board according to claim 1, whereinit is provided with a decor layer, whether or not with a pattern. 12.The board according to claim 11, wherein the pattern is a print directlyprovided on the board realized by means of a digital printer.
 13. Theboard according to claim 1, wherein said top layer or covering isresin-based, wherein the resin consists of a thermo-hardening resin. 14.The board according to claim 1, wherein it is provided with couplingmeans which allow coupling two of such boards to each other, which areconfigured such that they, in the coupled condition, provide for alocking according to a direction in a plane of the coupled boards andperpendicular to the coupled edges, and in a direction perpendicular tothe plane of the coupled boards; and that the coupling means areprovided with a means or element, more particularly in the form of amaterial layer or material strip, which provides for a sealing or for atensioning force, which presses the panels with pretension tensionagainst each other.